Still cleaner



.-1. w. BOOTH STILL CLEANER Feb. 8 1927.

Filed Feb. 26. 1924 4 SheSlZS--Shee4 1 aga..

Feb. 8, 1927e J. W. BOOTH ST ILL CLEANER Filed Feb. ze. 1924 4 sheets-sheet a Eltmmg:

J. W. BOOTH Feb. 8 Q 1 9270 STILL CLEANER 4 Sheets-Sheet 4 Filed Feb. 2s, 1924 Patented Feb. 8,

JAMES WILLIAM BOOTH, OF BARNSDALL, OKLAHOMA.

STILL CLEANER.

Application filed February 26, 1924. Serial No. 895,315.

The preseiitinvention relates an apparatus .tor cleaning high pressure stills.

At the present time, when cleaning high pressure stills, it is necessary to rshut down the still and permit it to cool'betore coininencing the manual or mechanical. cleaning of the still to remove deposits of carbon, tai', or coke from the sides and bottom ot the delay and loss of time.

It the still is .not perfectly clean so-called hot spots will form'resulting in the rupture of the still.

The present apparatus will eliminate these disadvantages and the still need not be r shut down as the cleaning is continuous.

The drawing off of the heavy precipitates from the bottom accordingly must tak-e place from time to time as this apparatus will remove the tar from the sides of the still, and this tar, being heavier than the oil, will naturallygravitate to the bottom lof the still, there to be drawn oil".

Ordinarily, carbon is .deposited on the sides of the still in the form of a tar-like substance, and b .latent heat, this substance is baked to a co e which is very ditlicult to Where my present apparatus is used there will be no time for the coke to forni as the deposits from the still Walls.

are constantly dislodged and-l Figure 1 Vis a fragmentary vertical section Figure 2 is a hoi'i 2-2 ol Figure 1;

' of a still withthe cleaner in position;

Zontal section along linc Figure 3 is a vertical section ol the operating gears 'for the c leaner g Figure 4- is av fragmentary horizontal section along line 4 4 Figure 5 is a fra ot Fig. 8; gmentary side elevation of the clutches for the operating gears;

Figure 6 1s a fragmentary vertical section Figure 7 is a hori 7--7 of Figure 6;

Figure 8 is a hori 81-8 of Figure 1;

r along line 6-6 of Figure 2;

zontal section along line zontal section along line Figure 9 is a side elevation showing a 5o inodiii-ed form oi. a scraper; and

Figure l() is a perspective view ot one ot the details ot the timing device.

In the drawings, reference numeral 15 represents aI cylindrical still for hydrocarbons. I ln the drawings, the still is represented as 'being erected with its axis vertically kpositioned but it is evident that the apparatus may equally well be applied to a horizontally positioned still. The upper end of the still has a neck 16 closed by a cover 17 forming a dome on the still. Similarly the bottom 18, which is preferably semi-spherical, has a central annular downward extension 19 which is closed by a cover 20. In this man- 6' ner a receptacle 21 Jior the heavy precipitates is termed at the bottom of the still and the center of the cover 2O is provided with a suitably valved drain pipe 22. The top and bottom covers 17 and 20 are firmly secured in position by bolts or the like.

Reference numeral 28 represents a. drive shaft which is revolubly mounted in a bushing 24 at the lower end thereof, see Fig. 6. This bushing is keyed, as at 24J, or in any other manner rigidly secured in a chair 25. This chair fits in the annular extension 19 and is provided with flanges engaging between tlie flanges of said extension and the cov-er 20 `so as to be firmly held in position. On the bushing 24 is loosely mounted a gear wheel 26 in mesh with a pinion 27 keyed on a feed sha-ft 28.

A latchndog 29 is pivoted7 as at 30,7011 the gear wheel 26, see'Figs. 6 and 7, and the bushing 24 is provided at one side with a notch 31 in which the latch-dog 29 is adapted to engage. It is evident that when so en gaged the latch-dog will firmly lock the gear whe-el 26 to the bushing 2li and as the latter is keyed in the chair 25, the gear wheel 2G will, accordingly, be stationary during such engagement, or, in other words, the pinion 27 on the feed shaft 28 will rotate with relation to the gear wheel 26.

A short distance labove the bushing 24. there is keyed to the shaft 23 a bracket 82 in which the feed shaft 28 is revolnhly mounted. At the outer end of this bracket is firmly secured by bolts 33 a scraper 34 having the contour of the semi-spherical bottom 18. As the drive shaft 23 turns it will communicate a rotary motion to the scraper 34 through the intermediary of the bracket 32 which is keyed and pinned fast to the shaft 23 as already described. Accordingly, the scraper will always participate in the rotation of the drive shaft 23 so that any heavy substances that may collect on the bottom 18 will be continuously stirred by the scraper and gradually carried down into the receptacle 21 from which they may subsequently be drained through the drain pipe 22.

As the scraper and the bracket 32 revolve around the axis of the drive shaft 23, the feed .shaft 28 will receive a planetary motion around the same axis and as the pinion 27 is of a different, preferably smaller, diameter than the gear wheel 26. the feed shaft 28 will be given a different speed of rotation to that of the drive shaft 23. The upper end of the feed shaft 28 is revolubly mounted in a bracket 35 which is rigidly secured on the drive shaft 23.

The feed shaft 28 is threaded between the bracket 32 and the bracket 35 and engages in a carriage 36 which is correspondingly threaded. This carriage has a sliding but non-revoluble connection with the drive shaft, or, in other words, the carriage is keyed on said shaft to slide up and down between the bracket 32 and the bracket 85, acr tuated by the feed shaft 28.

On the carriage v36 are secured a number of radial arms 37, four being shown in the drawings. On each arm is mounted a side scraper or brush 38. rllhe inner end of this brush contacts with the short arm of an elbow lever 39, on the long arm of which is secured a weight 4() preferably in such :i manner that it niay be adjusted in and out on the elbow lever. This arrangement cenipels the brush 38 to constantly pressI with its bristles 41 against the cylindrical side of the still.

In the carriage 36 is secured a downwardly directed linger 42 which is adapted to erH gage with an arm 82 on the latch dog when the carriage and brushes have dcscended to the bottom of the still and to diaengage the latch-dog from the notch 31 in the bushing 24, thereby permitting free rotation of the gear wheel 26 around the axis of the drive shaft 23 for a purpose that will be described later. A stop 83 is provided on the gear wheel for limiting the swing of the dog` In Fig. 9 is shown a modified forni of a side scraper for the still which, instead of a bristle'brush 38, has a comb 43 with teeth 44 adapted to contact with the inner side of the still. The corib is carried on a slide 96 guided upon the arm 37 and pressed outwardly in radial direction by means of a spring 46. It is evident that the scrapers 38 and 43 may be furnished on alternate arms in the same still or that all the arms may be provided with only one kind of scraper, as found most suitable for the particular still.

The upper end of the drive .shaft 23, which is preferably hollow, extends into the dome 45 and this end of the shaft is provided with a socket 84 fitting closely the square end 47 of an extension shaft 48 in axial alinement with the drive shaft 23. rlhe extension shaft is mounted to revolve in the top cover 17 and a bearing plate 49 at the upper end thereof. The cover is preferably constructed as a housing for the driving gears and the timine' device and has for this reason an upwardly ext-ended cylindrical wall 50 at the upper end of which are provided ears 51 upon which the bearing plate 49 rests and is held in position by means of bolts 52. .At the bottom of the housing is furnished an annular ledge 53 upon which a lower bearing plate 54 is deposited and kept in position by studs 55 secured in the ledge 53. The housing 50 including the top cover 17 is preferably a cast steel cylinder and on one side thereof is furnished a stuffing-box 56 for a motor driven main shaft 57. At the inner end of the main shaft 57 is secured a bevel pinion 58 which meshes with the bevel gear 59 secured on an intermediary shaft 60 revolubly mounted in the top andbottom bearing plates 49 and 54. Integral with the bevel gear 59 is shown a spur gear 61 in mesh with a corresponding gear 62 loosely mounted on the extension shaft 48. Similarly a second spur gear 63 is keyed to the intermediary shaft at the lower end thereof and meshes with an idler 64 mounted to revolve on the stub shaft 65 carried upon the bcaringplate 54. This idler 64 in turn meshes with a spur gear 66 loosely mounted on the extension shaft 48 as best shown in Fig. 3. rllhe gears 6l. 62, 63, 64 and 66.are preferably so selected that the ratio of revolution between shafts 60 and 48 is as one to one.

Between the spur gears 62 and 66 are inserted clutches 67 and 68 slidably but nonrevolubly mounted on the extension shaft 48. Each of these clutches has teeth 69 and 70 respectively, which are referably tapered or pointed in order to facilitate quick and easy engagement with corresponding teeth in the gear wheels 62 and 66. Each clutch has an axially slidable sleeve 71 between which and its clutch is inserted a compression spring 72 tending to force the sleeve and clutch apart. Each sleeve has an annular groove 73.

A slide 75 is mounted on -a rod 76, the axis of which is parallel to the axis of the drive and extension shafts 23 and 48, the rod being suitably supported between the top and bottom bearing plates 49v and 54. rllhis slide 75 has rigid fingers 77 adapted to respectively engage in the annular' grooves 73 of the clutch sleeves 71 in order to hold them a permanent distance apart. On the side of the slide opposite to that carrying the fingers 77 is a projecting stud 78, and this stud has preferably a roller 79 which engages in a cam groove 80, see Fig. 10, in a cam disk 81. The cam groove 80 is positioned eccentrically on the disk in order to actuate the sleeves 71 and effect engagement of the upper clutch 67 with the teeth of the spur gear 62 when the slide 75 stands at the upper end of its stroke and effect engagement of the clutch 68 with the gear 66 when the slide 75 is at the other end of its stroke. i

The timing device consists of a train of gears actuated from the main shaft 57 through the spur gear 66. A pinion is revolubly mounted on the extension shaft 48 below and keyed to the spur gear 66 so as to constantly revolve at the same speed at the latter. An idler 86 journaled on the bottom bearing plate 54 meshes with this pinion 85 as well as with a second pinion 87 secured on a worm spindle 88 mounted to revolve in bearings provided in the top and bottom plates 49 and 54. The worm 89 of this spindle engages with the worm wheel 90 keyed on a stub shaft 91 mounted horizontally in suitable bearings 92. The inner end of said stub shaft has secured thereon a pinion 93 meshing with a spur gear 94 secured on the same horizontal shaft 95 as the cam disk 81. The speed ratio of this train of gears has beenso selected that the cam disk 81 makes one revolution while the cleaning brushes complete their cycle from top to bottom of the still and back again or, in other words, the slide 75 completes a double stroke from top to bottom and return.

The clutch springs 72 are comparatively strong and permit only a short extension and their outer ends are secured to their respective clutches 67 and 68 so that, for instance, the lower clutch 68, as illustrated in Fig. 3, is suspended by the spring from its sleeve 71 without engaging the teeth of the bottom clutch. However', if the clutch were permitted to descend freely at the same ratio as the slide 75, it is evident that the teeth 70 would soon begin to engage the corresponding teeth in the bottom spur gear 66 and possibly before the teeth of the top clutch 67 had disengaged from the teeth of the upper spur gear 62. This would cause an interruption of the proper operation of the mechanism and a special retarding de vice is for this purpose furnished for the clutches.

The retarding device, best illustrated in Fig. 5, consists of a double armed lever 100, fulcrumed, as at 101, upon the side of the yoke 121. The yoke 121 spans the head 75 and is secured at either end or both ends to the rod 76 at points beyond the limits of movement of the slide so that it will not interfere with said movement, and, to economize space, the slide may he grooved in one side to accommodate the body of the yoke, as shown in Fig. 4. At each end of the lever is journaled, as at 102, a rocking arm 103 having a limited swinging motion on its journal. Each rocking arm 103 extends in the direction of the corresponding one of the clutches 67 and 68 and has a small friction roller 104 on its inner' end adapted to engage an annular collar 105 on the clutch when the lever 100 is tilted in one direction.

This tilting is accomplished by means of a raised cam 106 on the cam disk 81 engaging with a second roller 107 at the outer end of the rocking arm 103. The raised cam 106 is substantially of semi-circular extent so that when the roller 107 of one of the rocking arms 103 engages the top surface of the cam 106, the corresponding roller 107 on the other rocking` arm rolls along the face of the cam disk 81. The height of the e cam with relation to this face of the disk is such that the roller 104 of the upper rocking arm 103, for instance, as seen in Fig. 5, will be interposed in the path of the clutch collar 105 when the roll-er 107 of said arm rests upon the raised cam 106, while the roller 104 on the other rocking arm is simultaneously retracted out of the path of the collar 105 of the lower clutch 68. The

slopes 120 at the ends of the raised cam 106 l At 110 and 111 are shown inlet and out- V let oil ports to the housing` for keeping the gears well lubricated. ln order that this cold oil may not escape into the still a bushing 112 is provided in the cover 17 around the extension shaft 48. It will naturally not do to permit cold oil from the housing to drain into the still when in operation and this bushing only permits sufficient oil to pass down the shaft to properly lubricate the same, the quantity, however, being so sin-all that it will have no effect upon distillation of the oil in the still.

As the extension shaft 48 is slidably connected by means of its square end 47 with the socket 84 of the drive shaft 23 it will be possible to remove the entire housing, with the gears it contains, from the top of the still without disturbing the scrapers. 1t may also be possible to leave the housing and cover 17 in position and to remove the gears, mounted in the top and bottom bearing plates Ll2) and 541, assembled. 1n both cases the extension shaft 48 will be withdrawn from engagement with the socket S4 of the drive shaft 23 without the necessity of any special coupling. Another advantage of connecting the extension shaft with the drive shaft in the manner described and shown, is that considerable expansion will be permitted at the joint.

rl'he only difference between the apparatus for a vertical and a horizontal still is that the drive shaft will continue through the heads of the still and that thedrive shaft 23 and the feed shaft 28 have to be supported inedially in the still with two arms, the scrapers traveling from end to center and reverse.

lt has been found difficult to regulate the timing device for reversing the travel of the side scrapers because if they travel a small fraction in one direction beyond the desired turning point this discrepancy will gradually7 multiply so that the machinery will ultimately jam at top or bottom. A device has, accordingly, been introduced in this timing gear pern'iitting a greater number of revolutions in going down than in going up. In other words, the feed shaft 28 is stopped at a certain point so that the extra revolutions will cause no travel up or down of the scrapers, but they will continue to rotate in the same horizontal plane. The latch-dog 29 and operating finger Ll2 furnish the engaging and disengaging means of the feed shaft 28.

As the mechanism is completely enclosed in the still and in the housing it is iinpossible to observe whetherI it is functioning satisfactorily or not. A recording meter is therefore provided which has electrical connection with a contact plug 115, see Figs. 1 and S, mounted in suitable insulations 116 in the wall of the still. Any number of these contact plugs may be provided but there should at least be one near the top of the still and another near the bottom thereof, this is indicated in Fig. 1 of the drawings. These two contact plugs are then arranged so that when the scraper brushes 38 are at the end of travel in upward or downward direction. these brushes will sweep over the contact plug 115 thus completing the electric circuit so that a record on the meier will be given at the reversing points of the Scrapers.

rl`he operation of the device is as follows:

Supposing that the different parts of the apparatus are in their relative positions as indicated in Figs. 1, 8 and 5, that is to say, the side Scrapers have arrived at the bottom of the still and are ready to turn; supposing, further, that the main shaft '57 is revolving thereby actuating the spur gears 62 and 6G which are thus revolving at the same speed but in opposite directions they being loosely mounted on the extension shaft 48; the friction roller 10erof the upper rocking arm 103 is now in engagement with the annular collar 105 of the upper clutch 67, thereby compressing the spring 72 against the sleeve 71, which is shown at the upper end of its stroke, by the slide 7 The teeth of both the top and bottom clutches are out of engagement with lthe teeth of the corresponding spur gears and the shafts 23 and 48 are, accordingly, n'ioinentarily stationary. As the timing device, however, is continuously rotated by the lower spur gear 66 through the pinion 85, the cam disk 81 continues to turn. At the next fraction of a turn the friction roller 107 of the upper rocking arm 103 will slip down from the cam 106 to the face of the cam disk 81 while the corresponding roller on the lower rocking arm 103 will ride up on the cam 106. 1n this manner the lever 100 is swung on its fulcrum 101 thereby disengaging the friction roller 101- on the upper rocking arm 103 from the annular collar on the upper clutch 67, while the lower roller 104 is then thrust into the path of the annular collar 105 on the lower clutch 08. Directly the clutch 07 is released by the rocking arm 103 it is shot upward by its spring 72 so that its teeth 69 become practically instantaneously engaged with the clutch teeth on the upper spur gear 02. the clutch 67 being keyed to the extension shaft 4S now conununicates the rotation of the spur gear 02 to said shaft and through the same to the drive shaft 2?). The arm 37 with the side scraper BS will now start to revolve and, as the gear Wheel 26 is locked to the chair by the latch-dog 29 and the bushing Q4., the planetary motion of the bracket 32 will cause the pinion 2T to roll on the gear 26 and turn the feed shaft Q8 in its bearing bracket As, however, this feed shaft is threaded in the carriage S0 it will cause this carriage together with arms 37 to travel upwardly on the drive sha-ft Q3. accordingly, the Scrapers will follow a helical path around the side wall of the still. The bearing bracket 32 carries the bottom scraper 34. which consequently describes a circular motion around the axis of the drive shaft Q3 without leaving the bottom 18 of the still so that, while the carriage and the arms 87 are ascending7 the distance between the same and the boi.- tom scraper lelgradually increases.

l11 rom the above given description it will now be understood how the upper clutch G7 becomes disengaged from the spur gear 62 when the scrapers have arrived at the upper end of their travel and how the lower clutch engages with the lower spur gear 6G upon its release by the lower rocking arm 103. ,lt should here be noted that the cam groove 8O is set slightly ahead of the reversing action of the clutches. 'fhat is to say, the slide l5 arrives at the top end of its stroke before the side scrapers are reversed, so that, for insta-nce, the upper clutch will start on its way down before the side Scrapers reach the turning point and the clutch teeth will have had time to disengage at the right moment.

As has already been stated, the shafts 23 and 4:8, together with the Scrapers are permitted to make one or more idle turns before the scraper is permitted to again ascend after reaching the bottom of the still. This is accomplished by the operating finger 42 during its last descending turn to engage the arm 82 of the latch-dog 29. lhe latter is then instantly lifted out of the notch 31 in the bushing` 2li so that the gear wheel Q6 is free to rotate on the bushing. The wheel E26 is thus carried around with the bracket 32 and the feed shaft 28 and as no rolling motion then takes place between the pinion 27 and the gear wheel 26, the feed shaft 28 stops turning around its own axis, The distance between the carriage 36 with the scraper arms 37 and the bottom 18 of the still remains constant for a short while. is soon, however, as the upper clutch again engages with the top spur gear 62 and shafts 23 and 48 begin to revolve in the opposite direction, the operating finger l2 will strike the back of the arm 82 on the latch-dog 29 and force the same to engage in the notch 3l of the bushing Q11-, As the gear wheel 2G then becomes locked to the chair 25 the pinion 2T will be compelled to roll on the spur gear 26 thus rotating the feed' shaft 28 around its own axis. The carriage 36 together with the arms 37 on the side scrapers will, accordingly, begin to ascend.

Having thus described the invent-ion, what is claimed as new is:

l. Cleaning mechanism for stills comprising, in combination, a drive shaft rotatably mounted in the still, a carriage slidahly mounted on said shaft and rotatable therewith, cleaning elements on said carriage to contact with the wall of the still, means for automatically alternately rotating said shaft hrst in one direction and then in the opposite direction, and means operating in consonance with the rotation of the shaft to automatically move the carriage longitudinally of the shaft.

2. Cleaning mechanism for stills comprising, in combination, a drive shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable therewith, cleaning elements on said carriage to Contact with the wall of the still, means for automatically alternately rotating` said shaft first in one direction and then in the opposite direction, and means operating in consonance with the rotation of the shaft to automatically move the carriage longitudinally of the shaft, said means including a feed shaft h i threaded engagement with the carriage, means on the drive shaft for supporting` said feed shaft, a stationary gear, and a pinion on said feed shaft meshing with said gear.

3. Cleaning mechanism for stills comprising, in combination, a drive shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable therewith, cleaning` elements on said carriage to contact with the wall of the still, means for alternately rotating` said shaft first in one direction and then 'in the opposite direction, and means for moving; said carriage longitudinally of the shaft, said means including feed shaft having` threaded engagement with the carriage, means on the saidV drive shaft supporting` said feed shaft, a gear, a latch normally locking said `rear in fixed position'. a pinion on said feed shaft meshing with said gear, and a releasing element on said carriage for coaction with the latch to move the same to inactive position to permit free rotation of said gear.

4. Cleaning mechanism for stills comprising, in combination, a drive shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable therewith. cleaning elements arranged on said carriage to contact with the wall of the still, means for alternately rotating said shaft first in one direction and then in the opposite direction, and means for moving said carriage longitudinally of the shaft in opposite directions and in consonance with the alternate opposite rotation of the shaft, the said means including a feed shaft having' threaded engagement with the carriage, means on said drive shaft for supporting said feed shaft, a fired bearing for one end of the drive shaft, a gear rotatably engaged with the bearing, a latch upon the gear for coaction with the bearing to render the said gear stationa v with respect to thebearing, a pinion on the feed shaft meshing with the said gear, and a linger upon the carriage for coaction with the said latch when the carriage is rotating and has reached substantially the limit of its move ment in the direction of the said gear to move the latch to inactive position and permit f 1ee rotation of said `gear.

5. Cleaning mechanism for stills comprising, in combination, a drive shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable therewith, cleaning elements on said carriage to contact with the wall of the still, means for alternately rotating said shaft first in one direction and then in the opposite direction, and means for n'ioving` said carriage longitudinally of the shaft in opposite directionsl in consonance with the rotation of the shaft. in opposite directions, said shaft rotating means including gears freely rotatable upon the drive shaft, means for rotating said gears in opposite directions. a clutch for coaction with each of said gears slidabl'v mounted upon the said drive shaft, and means operating automatically to synchro-- nously operate said clutches and alternately effect their coaction With the respective gears at theI end of each longitudinal travel of said carriage.

6. Cleaning mechanism for stills comprising, in combination, a drive shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable therevvith, cleaning elements upon the carriage to contact With the Wall of the still, means for alternately rotating said shaft first in one direction and then in the opposite direction. and means for moving said carriage longitudinally of the shaft in consonance with rotation of the shaft in opposite directions, said shaft rotating means including gears freely rotatably mounted upon the drive shaft, means for rotating said gears in opposite directions, a clutch for coaction With each of said gears slidably mounted upon said drive shaft, and means operating automatically to synchronously operate said clutches and alternately effect their coaction- With the respective gears at the termination of each longitudinal travel of said carriage, said last mentioned means including a member mount-- ed for reciproca-tion with relation to the drive shaft, a sleeve slidably connected with each clutch, and a 'spring tending to separate each clutch and its respective sleeve, the said member coacting with both of said sleeves to effect their movement in unison.

7. Cleaning mechanism for stills comprising, inv combination, a shaft rotatably .mounted in the still, a carriage slidably mounted on said shaft and rotatable therewith, cleaning elements upon said carriage to contact With the Wall of the still, means for alternately rotating said shaft first in one direction and then in the opposite direction, and' means for moving said carriage longitudinally of the shaft alternately in opposite directions in consonance with rotation of the shaft in opposite directions, said shaft-rotatingT means including` gears mounted upon the drivel shaft for rotation with spect thereto, means for rotating said gears in opposite directions, a clutch for coaction With each of said gears slidably mounted upon said drive shaft, and means operating automatically to synchronously actuate said clutches and alternately effect their coaction w. i S- with the respective gears at the termination of each longitudinal travel of the carriage, said last mentioned means including a member mounted for reciproeation with respect to the shaft, a sleeve slidably connected with each clutch, a spring tending to separate -ach clutch and its respective sleeve, the said member engaging both of said sleeves whereby to effect their' movement in unison, a rotatable disc, and means for rotating the same, the said disc having means coacting with said member to reciprocate the same.

8. Cleaning mechanism for stills comprising, in combination, a shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable there- With, cleaning elements upon said carriage to contact with the wall of the still, means for alternately rotating` said shaft first in one direction and then in the opposite direction, and means for moving said carriage longitudinally of the shaft alternately in' opposite directions in` consonance With rotation of the shaft in opposite directions, said shaft-rotating means including gears mounted upon the drive shaft for rotation with respect thereto, means for rotating said gears in opposite directions, a clutchl for coaction with each of. said' gears slidably mounted upon said drive' shaft, and means operating automatically to synchronously aetuate said clutches and alternately effect their coaction with the respective gears at the termination of cach longitudinal travel of the carriage, said last mentioned means including a member mounted for reciprocation With respect to the shaft, a sleeve slidably connected with each clutch, a spring tending to separate each clutch and its respective sleeve, the said member engaging both of said sleeves whereby to effect their movement in unison', a rotatable disc, means for rotating the same, the said disc having means coacting with said member to recipro- 4cate the same, a centrally fulcrumed lever upon the said member, a finger projecting from each end of the lever in the direction of a respective one of the clutches, a cam upon said disc coactin'g withy the fingers to effect rocking of the lever and corresponding movement of the fingers whereby to interpose one of said ngers in the path of the respective clutch and simultaneously retract the other finger to position it out of the path of the respective clutch.

9. Cleaning mechanism for stills comprising, in combination` a drive shaft rotatably mounted in the still, a carriage slidably mounted on said shaft and rotatable there- With, cleaning elements on said carriage to contact with the Wall of the still, means for alternately rotating said shaft firstv in one direction and then in the opposite direction, and means for moving` the carriage longitudinally of the shaft in opposite ldirections in consonance with the rotation of the shaft in opposite directions, said shait-rotating means including gears freely rotatable upon the shaft, means for rotating said gears in opposite directions, a clutch for coaction With each of said gears slidahly mounted upon the shaft, means operatingl automatically to synchronously operate said clutches and alternately eliect their coaction with the respective gears at the end of each longitudinal travel of the carriage, and means for retarding the engagement of the clutches With the respective gears.

In testimony whereof I alix my signature.

JAMES WILLIAM BooTI-I. [L Si] 

